The present invention relates to a transceiver system and the operation method thereof, and particularly it relates to a technique useful to arrange a transceiver system operable to communicate with partners linked therewith, and minimize the increase in power consumption.
In recent years, electronic devices having a function for network communication using a network such as Ethernet (registered trademark) have been in common use. In general, such network is constituted by LAN (Local Area Network) installed in a building, a house or the like.
LAN communication is classified into an infrastructure-communication mode, and an ad hoc communication mode. In the infrastructure-communication mode, LAN communication terminals or stations make connections via hubs at access points. However, in the ad hoc communication mode, LAN terminals or stations can communicate without going through access points' hubs. In the infrastructure-communication mode, it is indispensable to set an infrastructure equipment at an access point, whereas the ad hoc communication mode does not need such infrastructure equipment.
However, in the ad hoc communication mode, a receiving-side LAN terminal cannot determine when LAN terminals issue a transmitted packet, and therefore the receiving-side LAN terminal needs to keep working at all times. A LAN terminal includes a physical-layer transceiver (PHY: PHysical Layer), and a logical-layer MAC (Media Access Controller). The physical-layer transceiver can be adapted to various physical characteristics such as the communication speed and communication range of LAN communication media. Further, MAC (Media Access Controller) controls the memory transfer of data packets to send/receive. In other words, the physical-layer transceiver of a LAN terminal is connected to a number of linked partners through LAN, and executes data packet communications therewith, whereas MAC (Media Access Controller) executes packet transfer with the aid of DMAC (Direct Memory Access Controller) performing memory transfer; the action of DMAC is under the control of CPU (Central Processing Unit). Hence, in the ad hoc communication mode, the operation that a LAN terminal performs uninterruptedly at all times increases the power consumption by the physical-layer transceiver of the LAN terminal.
Although there is no description about the ad hoc communication mode, the way of dynamically shutting down Etherlink during Etherlink communication between a set of a transmitter and receiver is described by Maruti Gupta et al, “Dynamic Ethernet Link Shutdown for Energy Conservation on Ethernet Links”, IEEE International Conference on Communications, 2007. ICC '07, 24-28 Jun. 2007, PP. 6156-6161. Further, although there is no description about the ad hoc communication mode, a gigabit Ethernet controller which is set to Smart Power Down mode when no signal is detected on the wire is described in: 82541 Family of Gigabit Ethernet Controllers, Datasheet Intel Corporation, at http://jp.ic-on-line.cn/IOL/datasheet/82541—4432111.pdf, which is a result of searching the Internet on Mar. 30, 2010.